fix(engine): enforce tool use for stop/pause/cancel commands

[serrrfirat]

Summary

• Add stop/pause/cancel/halt/disable to the orchestrator's tool-intent nudge and execution-obligation detectors so the LLM is forced to actually call mission_pause/mission_list instead of narrating about them
• Add bare imperative detection ("stop", "stop pinging", "pause") with startswith guard to avoid false positives like "I can't stop"
• 5 regression tests covering true positives and false negatives for both detectors

Closes #2808

Test plan

• cargo fmt — clean
• cargo clippy --all --benches --tests --examples --all-features — zero warnings
• cargo test -p ironclaw_engine — 466/466 pass
• New tests: signals_tool_intent_stop_pause_cancel, signals_tool_intent_no_false_positive_stop_discussion, signals_execution_intent_stop_pause_cancel, signals_execution_intent_bare_stop, signals_execution_intent_no_false_positive_stop_in_sentence

🤖 Generated with Claude Code

[gemini-code-assist]

Code Review

This pull request adds support for 'stop', 'pause', 'cancel', 'halt', and 'disable' intents in the orchestrator, including updates to tool and execution intent logic and new unit tests. Feedback suggests expanding the execution phrase lists for consistency and refactoring the bare command detection to handle punctuation by using word-based splitting.

[gemini-code-assist]

For consistency with the verbs added to signals_tool_intent, please include the "halt" and "disable" variants in EXEC_PHRASES.

Suggested change

	"stop it", "stop that", "stop this", "stop the ",
	"pause it", "pause that", "pause this", "pause the ",
	"cancel it", "cancel that", "cancel this", "cancel the ",
	"stop it", "stop that", "stop this", "stop the ",
	"pause it", "pause that", "pause this", "pause the ",
	"cancel it", "cancel that", "cancel this", "cancel the ",
	"halt it", "halt that", "halt this", "halt the ",
	"disable it", "disable that", "disable this", "disable the ",

[gemini-code-assist]

Add "please halt " and "please disable " to the list of polite execution phrases.

Suggested change

	"please stop ", "please pause ", "please cancel ",
	"please stop ", "please pause ", "please cancel ", "please halt ", "please disable ",

[gemini-code-assist]

The current bare imperative detection is too strict and misses commands with trailing punctuation (e.g., "stop.") or commands on the first line of a multi-line message. Using a word-based check on the first word is more robust and handles punctuation correctly.

Suggested change

	trimmed = lower.strip()
	IMPERATIVE_STARTS = ["stop ", "pause ", "cancel ", "halt "]
	BARE_COMMANDS = ["stop", "pause", "cancel", "halt"]
	if trimmed in BARE_COMMANDS:
	return True
	if any(trimmed.startswith(s) for s in IMPERATIVE_STARTS):
	return True
	# Bare imperative commands at the start of the message.
	# "stop", "pause", "cancel", "halt", "disable" are unambiguous commands
	# that don't match the "verb + pronoun/article" pattern above.
	# Checking the first word avoids false positives like "I can't stop".
	words = lower.split()
	BARE_COMMANDS = ["stop", "pause", "cancel", "halt", "disable"]
	if words and words[0].rstrip(".,!?") in BARE_COMMANDS:
	return True

References

1. When detecting commands or keywords in a string, use token-based or word-boundary checks instead of simple substring containment to avoid false positives (e.g., 'sync' matching 'nc', 'ghost' matching 'host').

[serrrfirat]

Addressed all review feedback from gemini-code-assist:

1. halt/disable in EXEC_PHRASES — Added "halt it/that/this/the" and "disable it/that/this/the" for consistency with signals_tool_intent (4304d2f, 9b10521)
2. "please halt/disable" — Added both to polite execution phrases (4304d2f, 9b10521)
3. Bare imperative punctuation + disable — Strip trailing punctuation via rstrip(".,!?;:") so "Stop." and "cancel!" match; added "disable" to BARE_COMMANDS and IMPERATIVE_STARTS (4304d2f, 9b10521)

All 468 engine tests pass, fmt clean.